I got this T4004 in a trade, and it's in great shape, minimal scratches, super clean inside. The audio coming out of it is very distorted, and cuts out sometimes. It's almost like a scratchy gain pot, but it does it when the gain is sitting still. So it almost makes me think a cap is bled down or trying to crap out on me. I couldn't find any burnt spots, discolored anything, or any swollen caps inside. All looked to be fine. I swapped in my T3002 during testing and all was clean sounding, so i know it's not the cables, speaker or source.
Here's a video:
This time the distortion isn't the camera mic